1. Field of the Invention
The present invention generally relates to an apparatus and method for wireless communication with multiple stations (STAs), and, more particularly, to a mmWave (millimeter wave) communication system and method for updating NAV timers in directional communication with multiple STAs.
2. Relevant Background
In wireless communication under 802.11 standard, most frames transmitted carry a duration field, which is for reserving the use of a channel to a transmitting/receiving STAs for a specific time. Because each channel has other STAs not active for a frame, the duration field signals to other STAs the reserved status of a channel within a duration for with the transmitting and receiving STAs.
A Network Allocation Vector (NAV) Timer in a STA accounts and counts down the time of which the channel will be reserved from the duration field. STAs will normally have a buffer to store the NAV timer and to count down time from the reserved duration.
As such, a STA in 802.11 mode requires only one buffer for the NAV Timer as a STA in a 802.11 mode normally transmits and receives with an omnidirectional antenna reserved channel can be accessed by all STAs within range of the omnidirectional antenna. Therefore, the NAV Timer needs only to update with the longest duration field received in the channel. However, this NAV Timer configuration is not optimal for directional antenna operation as not all STAs in the channel is within range of the directional antenna and a STA can detect multiple simultaneous transmission.
Accordingly, there is a need in the art for a mechanism to update the NAV timer in directional communication with multiple STAs, such as in mmWave communication.